This actually happened many times in the past, but I was quick enough to reboot the server to fix it. I am not sure what's causing it, but it may be a connection issue. I will reboot the server and it should go back to normal.

I just noticed it too. I will look into the database server logs. Until I find the cause, I will not reboot the system for troubleshooting purposes. So you may see the error messages--please ignore or refresh the page.